1. Field
The present invention relates to an apparatus and method of calculating the position of a robot, and, more particularly, to an apparatus and method of calculating the position of a robot, which is capable of determining the position of a robot and creating a map of the surroundings of the robot which account for the travel state of the robot.
2. Description of the Related Art
Techniques to determine the position of a robot and creating a map of the surroundings of the robot are one of the most important techniques in the manufacture of a robot. Simultaneous Localization And Map-building (SLAM), which involves the use of a camera or a laser distance meter, has recently been developed.
A SLAM algorithm, which uses a Kalman filter or a particle filter, is divided into a prediction operation and a correction operation. In the prediction operation, the displacement of a robot is measured. In the correction operation, the position of the robot as calculated in the prediction operation is corrected based on absolute coordinate data provided by a camera or a laser distance meter.
In general, in the prediction operation, the number of rotations of each wheel of a robot is measured using an encoder, and the relative position of the robot is calculated based on the result of the measurement. However, if the robot is in a slip state in which wheels slip on the floor, the relative position of the robot may not be able to be precisely determined by an encoder, and, thus, the general performance of a SLAM algorithm may deteriorate.
Therefore, it is necessary to develop ways to properly calculate the position of a robot which account for the travel state of the robot, i.e., whether the robot is in a normal state or in a slip state.